A fluid distributor is known comprising a surface having a plurality of orifices communicating with a distribution passage under the surface and each provided with a respective spring-loaded ball-type check valve. The top of the ball extends slightly above the surface of this distributor so that when depressed against the spring force fluid can flow out of the hole. Thus an object depressing one of the balls will be lifted at least partially by the current of air blowing out of the hole. Such an arrangement is extremely expensive. In addition in such an arrangement it is necessary that the upper surface be rather rigid so that it is impossible to use this type of arrangement as a mattress or the like.
Various devices have been suggested to support an invalid or other bed-ridden person on a cushion of air. It is thus known to provide a plurality of holes in the mattress which are connected to a source of air under pressure and whose output can be regulated either by vanes or barriers on the surface of mattress to allow for the shape of the body of the user. All such systems are relatively complicated and must be readjusted for each new user or each time the same user moves.
Another attempted solution is a type of air mattress which is formed of a succession of independently parallel tubes adapted to be inflated. The tubes are subdivided into two groups, every other tube belonging to the same group, so that it is possible to inflate every other tube, leaving the other tubes lying between them uninflated, and then to inflate the hitherto uninflated tubes and deflate the previously inflated tubes. In this manner pressure on the bed-ridden user is constantly changed so that the possibility of bed sores is greatly decreased. In addition such an arrangement is provided between the tubes with groups of throughgoing holes that allow air to blow up through the mattress and flow over the body of the user. Such a system is relatively complicated and does not truely support the body of the user on the cushion of air.
A system has been suggested for transporting objects along a corridor. The surface of the corridor or passage is made of an elastically deformable material which is longitudinally split so as to give access to a longitudinal air distribution canal of square section which extends under the transport surface. The two horizontal lips on each side of the split are adapted to separate when a weight is placed on the transport surface so as to allow a current of air to escape from the distribution passage and at least partially support the charge. Such a system has been suggested but in reality has never been highly effective as the relatively long slot opened by the weight of the charge allows an excess amount of air to escape from the distribution passage and therefore does not properly support the charge. In addition if sufficient pressure is provided in the distribution passage to support the charge the lips would have to be extremely rigid normally to lie shut so that the weight would have to be extremely large to open them.